Grinding machine for plastic flooring



May 14, 1940. s. P. GRANE LL 2,200,921

GRINDING MACHINE FOR PLASTIC FLOORING Filed April 24,1939 2 Sheets-Sheet 1 73 INVENTUR EEF! E-RANELL A-r-rcIHNEYs May 14,1940. G. P. GRANELL' 2,200,921

GRINDING MACHINE FOR PLASTIC FLOORING Filed April 24, 1939v 2' Sheets-Sheet 2 w 4 1 0 /4 H I 3 v F1515. 54 2 INVENTDR Er. F. E'rRAN ELL N BY 07 071 I 4 ATTD RN EYE Patented May 14, 1940 UNITED STATES PATENT OFFICE GRINDING MACHINE FOR. PLASTIC FLOORING 3 Claims.

My invention relates to improvements in grinding machines for plastic flooring and the object of -the invention is to devise a machine which will contact a maximum area of floor surface,

which may be handled by the operator with a minimum amount of effort and readily moved from one location to another, in which the grinding units may be easily gotten at for the purpose ofremoval and renewal and in which means is provided for easily supplying water to the grinding units, and it consists essentially in the arrangement and construction of parts as hereafter more particularly explained. 7

Fig. 1 is a perspective view of my device in the grinding position.

Fig. 2 is a similar view to Fig. 1 showing my device in position for removing or renewing the grinding stones.

Fig. 3 is a perspective detail of the carriage.

Fig. 4 is an end elevation of my device.

Fig. 5 isan enlarged plan'view of the gear box with'the cover removed.

Fig. 6 is a sectional view on line 6-6 Fig. 5.

.In the drawings like characters of reference indicate corresponding parts in each figure.

'I'hebody of the grinder consists of a gear box 1. A'base plate 2 connected together byend walls 2* and 2 and bearing sleeves 3 recessed at their endsat 4 and 5 to receive upper and lower bearings 6 and 'l in whichare mounted the grinder shafts 8 supported from vertical movement by the annular enlargement 9 resting on the upper hearing 6 and the side standards 3*.

To the upper end of each shaft 3 is secured a spiral gear ill and to the lower end is secured the grinding element H provided with radial grinding stones l2 which contact with the surface to be ground.

Each grinding element H is connected to a disc I3 suitably secured to the shaft 3 to revolve therewith. Discs M of flexible material are interposed between the discs [3 and grinding elements.

The discs 13 are provided with suitably spaced bosses l5 to which the discs I4 are secured by bolts I6. The units H are provided with bosses ll to which the discs M are secured by bolts [3 intermediately between the bosses 15. it is a spiral spring extending between the disc [3 and the grinding element H.

I do not describe this connection further in detail as it is covered by a prior patent, save to say that it allows the grinding stones accommodating 2K). The gear box I is divided into transverse compartments I and I each containing a pair of gears In, each pair being driven by a worm 2i secured to a driving shaft 22 mounted in bearings 23 and 2:1. The bearing 24 is provided with a cone bearing 25 and the bearing 23 with ball bearings 26 and'Z'l.

The transverse compartments i and I" are separated by the wal1'28 recessed at 29 for the passage of the shaft 22 and provided at each side of such recess with an orifice 30 from each of which extends a horizontal orifice 32.

Studs 34 and 35 are provided with reduced inner portions 34 and 35* extending through the ori fices 32 into the orifices 30 and have screwed thereon securing nuts 36'to hold the studs 34 and 35 securely in place. The outer ends of the studs are reduced at 3'! and 38 for a purpose which will hereafter appear.

The gear case I is provided with a cover 38 on which is mounted and secured a driving motor 4B, the shaft ll of which is provided with a pulley 42 connected by belts 43 to the pulley 44 secured to the shaft 22. '45 is a switch box for control ling the current supply to the motor. A water supply pipe t6 to which a hose or other means of supplying water thereto leads through the wall 2 to the centre of the baseZ through which it extendstc a discharge 4! for supplying lubricating water to the surface of the floor and to the grinder units.

I will now describe the carriage by which the grinder is moved from one room or location to another.

The carriage consists of a lever frame comprising side members 43 and 49 connected together by transverse rods 50 and 5| and intermediately between rods but closely adjacent the rod 50 by a transverse angle bar 52. From the ends of the angle bar 52 extends arms 53 and 54 having upwardly extending ends 55 and 56 having forked extremities til and 58 into which the reduced stud portions 31 of the studs 34 and 35 fit so as to rotate therein between the ends of the studs and the washers 59 secured on the studs by the nuts 60.

Stud shafts BI and 62 extend outwardly from the bars 48 and 49 just below the transverse rod 50 and on which are mounted the rubber tired carrier wheels 63 and 64, forming the fulcrum point on which the lever frame swings. The outer or operative end of the carrier frame is provided with laterally extendinghandles 65 and 66. Therefore, when the handles '55 and 66 are depressed the carriage frame fulcrums on the wheels 68 and 64 raising the opposite end of the lever frame formed by the forked ends 51 and 58 to raise the grinder body.

A counterweight 6'! is slidably mounted between the side members 48 and 49 which rest in the operative position of the machine against the buffer pins 68 and 69, the movement of which are yieldably resisted by any suitable means such as a spring within the tubular sockets l0 and H. In the position of. the counterweight 61 as shown by full lines in Fig. 1 the weight of the body of the machine is to a certain extent balanced so that the friction between the grinding members and the flooring would not be too great and oppose the motor to such an extent as to cause it to burn out.

When the weight 61 is drawn by the handle 61* into the dotted position at the upper end of the frame and when the machine is not in operation, it serves to further counterbalance the weight of the machine and allow of the operator easily forcing down the upper end of the carrier frame by means of the handles 65 and 66 to lift the machine away from the flooring and the grinding members out of contact therewith. when in this position the brackets 61 bear against the lower ends of the frame members 48 and 49 and the machine may be rolled on the carrier wheels 63 and 64 to any new location.

vWhen the counterweight is raised to the dotted line position shown in Fig. 1 by pulling up on the handle 61* the inclined end 12 of the pivoted gravity latch 12 engages the pin or bolt 13 raising the latch so that the notch 14 thereof drops in engagement with the pin or bolt 13 locking the weight in its upper position.

When it is desired to change the grinding stones when they become broken or worn, the handles 65 and 66 are further depressed to the position shown in Fig. 2.

When the motor is in its normal position as in Fig. 1 a stop projection 15 extends upward therefrom. By depressing the handles 65 and 66 to the floor level and by then rotatingthe body of the machine on the studs 34 and 35 in the forks 51 and 58 in the direction of arrow, the stop 15 is carried into engagement with the cross rod 50 in the position shown in Fig. 2, holding the .body of the machine in an inverted position with the grinding units exposed and readily gotten at. By this means any stooping or awkward manoeuvring on the part of the operator to remove and replace a grinding stone is avoided.

If desired the carriage may engage the body from either end as circumstances require.

What I claim as my invention is:

1. A grinding machine for plastic flooring comprising a grinder body, grinder units mounted in the body to rotate beneath the same, means carried by the body for rotating the units, a lever frame, carrier wheels upon which the frame is fulcrumed, arms extending inward from the fulcrum point andat each side of the grinder, a weight adjustable longitudinally of the frame for counterbalancing the grinder body and means for automatically locking the counterbalaneing weight when adjusted to the outer end of the frame.

2. A grinding machine for plastic flooring comprising a grinder bod-y, grinder units mounted in the body to rotate beneath the same, means carried by the body for rotating the units, a lever frame, carrier wheels upon which the frame is fulcrumed, arms extending inward from the ful- 'CILU'D. point and at each side of the grinder, ,a weight adjustable longitudinally of the frame for counterbalancing the grinder body, means for automatically locking the counterbalancing weight when adjusted to the outer end of the frame, and bufiers at the inner end of the frame for receiving the counterweight when released from the locking means.

3. A grinding machine for plastic flooring comprising a grinder body, suitably driven grinder, units mounted in the body, a lever frame, carrier wheels upon which the frame is fulcrumed, arms extending inward from. the fulcrum point and at each side of the grinder, means for pivotally mounting the body between the arms whereby the body when raised from the floor by the lever frame may swing to an inverted posi tion, a projection extending upward from the body and a cross bar carried by the frame with which the projection engages tohold the body stationary when in an inverted position and the grinding units in convenient position for replacement.

GEORGE PETER GRANELL. 

